Food labeled as gluten-free must now adhere to a uniform standard in the U.S. as the result of a new federal requirement.

The Food and Drug Administration defined “gluten- free” as food that contains less than 20 parts per million of gluten, a protein found in wheat, rye and barley. Food makers such as Minneapolis-based General Mills Inc., which has rolled out a line of gluten-free Betty Crocker products, will have one year to ensure labels on their cans and boxes meet the standard.​